Kahn stands at 5'6". He lives with his wife Minh and his daughter Connie next door to the Hill Family. Kahn works in the information technology industry as a systems analyst. He originates from Luang Prabang, Laos. He first moved to Anaheim, California but left due to "neighbor problems" as told by Minh, as she tells him to get along with the neighbors - saying she was tired of "running" so much, first from Laos, then from California. He attends the Nine Rivers Country Club, which is comprised of almost all Asian members. Kahn is known to frequently "suck-up" to Ted Wassanasong, a fellow Laotian on the membership committee of the Country Club, who is not particularly fond of him at all. Kahn usually tries to push Connie to date Ted's son, Chane, rather than her dating Bobby, as he fears Bobby will drag her down from her studies and future. Kahn has a love-hate relationship with his Rainey Street neighbors, often insulting them by calling them "Rednecks" and "Hillbillies" and displaying a superiority complex, and other times showing kindness. He doesn't especially have friends in the neighborhood, most wanting to avoid him completely (even Bill) and being delighted when something bad happens to him. He does seem to be neutral to Boomhauer, as Boomhauer usually isn't the ringleader or causes problems. He also will come to Hank for advice at times. Kahn has been known to live with an unspecified form of bipolar disorder (referred to, at the time, as manic depression) in the episode "Lost in Myspace" and in "Just Another Manic Kahn-Day," Kahn has been shown to struggle with taking his medication.
Kahn works as a systems analyst in the Arlen area for seasons 1-3. In season 3 he is fired for leaking confidential information about a contract with the U.S. Army in an attempt to impress Hank. After a brief period of intermittent employment at minimum-wage jobs during which his family's entire savings are drained, Kahn secures a new job that pays $20,000 more per year than his former position, but is located in Houston, which is a three-hour commute from Arlen and a city that Kahn personally hates. In season 12, Kahn's job allows him to begin working from home. It is never explained how he handles the six-hour round trip to work in the meantime, though the fact that he is rarely seen in the alley in the evenings may indicate that he stays in Houston during the week and only returns to the family home on weekends.
Kahn was born and raised in Laos and subsequently spent time in Cambodia before immigrating to the United States. Due to growing up under two repressive Communist regimes, Kahn is the most conservative and patriotic of the regular characters, often exceeding even Hank in his staunch pro-Americanism. His chief recreational activity appears to be singing along passionately to popular American songs of the 1970s and 80s, a behavior which appears in multiple episodes and reaches a culmination in Pour Some Sugar on Kahn when he becomes involved in karaoke.
- Kahn's last name "Souphanousinphone" is a pun on "sousaphone", which is a type of tuba.
- His name is an anagram of Hank's name
- Kahn's license plate says "king kahn", a homage to King Kong
- In the episode "Uh-oh, Canada", it was revealed that Kahn spent 2 years in the Killing Fields, a name given to the sites in Cambodia in which the notorious Khmer Rouge had killed and buried large numbers of people
- Kahn's mother refers to him as Kohng Koy Kahn, which literally means, "It is mine Kahn" in Laotian. There is debate if this is his "Full first name", but it is more likely a pet name calling him her Kahn. Her name is Laoma and she had a romantic relationship with Bill, much to Kahn's horror. He briefly broke them up, but they reunited.
- Kahn is very skilled in martial arts. In The Redneck on Rainey Street, he defends himself using moves from Pencak Silat, a martial art originating in Indonesia.
- For most of his on-screen appearances, Kahn drove a blue 1980s Toyota Ace Van. Exceptions are (1) in "Tankin' It to the Streets", where Kahn is seen driving a blue 1996 Chevrolet Suburban, (2) another episode where he is seen driving a grey/silver 2003 Nissan Maxima, and (3) the episode in Lucky's debut, driving a red 1980 Chevrolet El Camino. The suburban was destroyed in its debut episode, and the silver car was destroyed by Lucky's friends in the debut of the El Camino. He has rented cars on several occasions such as when Minh ran for the school board, and was given company cars. Kahn has no Ferrari in his garage; He was referring to himself when he mentioned this. The only time more than one car was seen at the same time was when he was towing the blue van with his silver car, about to commute to his new job in Houston.
- The episode "Just Another Manic Kahn-Day" centers around Kahn's manic depression. However, it was first revealed in the episode "Lost in MySpace" when Peggy discovers the information on the titular website.
- In the episode "Naked Ambition", it is revealed that Kahn owns a speedboat named "Laotian in Motion."
- Kahn has special contempt for the Hills, but appears to see them as his friends at times - as Minh is good friends with Peggy, Connie is one of Bobby's best friends / ex-girlfriend, and Kahn will sometimes go to Hank for advice or hangs out with the gang in the alley.
- In the episode "Maid in Arlen", Kahn is playing a keyboard, suggesting he is possibly skilled in playing the instrument.
- Kahn owns a car wash from an attempt to get rich, but now is stuck there in order to pay his second mortgage.
- Kahn also started to make his own Tom Vu styled Get Rich Quick Videos with Minh as the Camera Operator and Director.
- In "Just Another Manic Kahn-Day", he is also skilled in painting, as a self-portrait is seen during one of his manic episodes.
- He has worked at numerous places, including Strictland Propane.
- Hank recruited Kahn to make monstrous grills for Strictland.
- In the episode “Maid in Arlen“, Laoma says that Khan’s father died from a heart attack.
- Jumpin' Crack Bass (It's a Gas, Gas, Gas)
- The Son That Got Away
- The Company Man
- Bobby Slam
- Three Days of the Kahndo
- Traffic Jam
- The Final Shinsult
- Death of a Propane Salesman
- And They Call it Bobby Love
- Pregnant Paws
- Good Hill Hunting
- De-Kahnstructing Henry
- The Wedding of Bobby Hill
- Love Hurts and So Does Art
- Take Me Out of the Ball Game
- Aisle 8A
- Happy Hank's Giving
- High Anxiety
- Naked Ambition
- Movin' On Up
- Won't You Pimai Neighbor?
- Meet the Propaniacs
- Peggy's Fan Fair
- Get Your Freak Off
- The Fat and the Furious
- Bad Girls, Bad Girls, Whatcha Gonna Do
- Dances With Dogs
- The Texas Skillsaw Massacre
- Maid in Arlen
- The Powder Puff Boys
- Four Wave Intersection
- The Minh Who Knew Too Much
- "Pour Some Sugar on Kahn"
- Dia-BILL-ic Shock
- Earthy Girls are Easy
- Uh-oh, Canada
- The Boy Can't Help It
- Just Another Manic Kahn-Day
- To Sirloin With Love
- MINH: Kahn, we have no nanny for Connie.
- KAHN: Oh, cruel, cruel fate! This Maui speech could be my stepping-stone from systems analyst to senior systems analyst!
- "Tell kids, SpongeBob in front of school." "I don't know what kids like."